1. Field of the Invention
This invention relates in general to extension drive tools for transferring torque and more specifically to an extension drive for a socket wrench extension having a plurality of torque receiving appurtenances.
2. Description of the Related Art
Socket wrenches are commonly used to turn fasteners, such as bolts. A socket is placed over the bolt and a drive tool is inserted in a socket cavity for transferring torque to the socket wrench. Typically a ratchet driver is used directly as a drive tool. Often an elongated extension drive is used between the ratchet driver and the socket. Extensions sometimes allow work to be performed in narrow or confined areas where a ratchet wrench could not be placed or turned. Sometimes there is room for an extension but no room at all for a ratchet drive, i.e. there is no room to add anything to the length of the extension. Sometimes, it is possible to transfer torque to the drive only axially. Sometimes, the proper ratchet drive is not available.
Often, also, in situations requiring low torque, such as starting a bolt or un-screwing a bolt after loosening, a user will simply turn an extension by hand. Typical extension drives are round smooth metal, often slippery, that are not adapted for applying a torque except by way of a ratchet drive.
Therefore, it is desirable to have an extension drive having a variety of torque receiving appurtenances without sacrificing the advantages of small size.
U.S. Pat. No. 4,004,476 of DeVrou titled "SOCKET WRENCH EXTENSION GRIP" recognizes the desirability of being able to apply torque to an extension drive and proposes a flexible gripable cover for the extension. The grip can only be used to transfer small amounts of torque.
U.S. Pat. No. 4,825,733 of Chinchar proposes a wrench having a variety of torque receiving appendages. The wrench is large and not suitable to small space requirements.